XML Tree Viewer using SAX Parser in JAVA with Jtree,JFileChooser component of Swing

I am going to create a utility application in JAVA for reading the XML document using SAX parser. The application will look like:

Input File :

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Movies>
	<Movie Actor="Aamir Khan" Name="Lagaan" Type="BollyWood">
		This is node description for Movie Lagaan
	</Movie>
	<Movie Actor="Aamir Khan" Name="Andaaz Apana Apna" Type="BollyWood" />
	<Movie Actor="Salman Khan" Name="Dabang" Type="BollyWood" />
	<Movie Actor="Salman Khan" Name="Wanted" Type="BollyWood" />
	<Movie Actor="AKshay Kumar" Name="Mujhse Shadi karoge" Type="BollyWood" />
	<Movies2011>
		<jan> Yamla Pagala Deewana </jan>
	</Movies2011>
</Movies>

Code:

package com.G2.SAX;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.filechooser.FileFilter;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class XMLTreeViewer extends DefaultHandler {

	private JTree xmlJTree;
	DefaultTreeModel treeModel;
	int lineCounter;
	DefaultMutableTreeNode base = new DefaultMutableTreeNode("XML Viewer");
	static XMLTreeViewer treeViewer = null;
	JTextField txtFile = null;

	@Override
	public void startElement(String uri, String localName, String tagName, Attributes attr) throws SAXException {

		DefaultMutableTreeNode current = new DefaultMutableTreeNode(tagName);

		base.add(current);
		base = current;

		for (int i = 0; i < attr.getLength(); i++) {
			DefaultMutableTreeNode currentAtt = new DefaultMutableTreeNode(attr.getLocalName(i) + " = "
					+ attr.getValue(i));
			base.add(currentAtt);
		}
	}

	public void skippedEntity(String name) throws SAXException {
		System.out.println("Skipped Entity: '" + name + "'");
	}

	@Override
	public void startDocument() throws SAXException {
		super.startDocument();
		 base = new DefaultMutableTreeNode("XML Viewer");
		((DefaultTreeModel) xmlJTree.getModel()).setRoot(base);
	}

	public void characters(char[] ch, int start, int length) throws SAXException {

		String s = new String(ch, start, length).trim();
		if (!s.equals("")) {
			DefaultMutableTreeNode current = new DefaultMutableTreeNode("Descrioption : " + s);
			base.add(current);

		}
	}

	public void endElement(String namespaceURI, String localName, String qName) throws SAXException {

		base = (DefaultMutableTreeNode) base.getParent();
	}

	public static void main(String[] args) {
		treeViewer = new XMLTreeViewer();
		// treeViewer.xmlSetUp();
		treeViewer.createUI();

	}

	@Override
	public void endDocument() throws SAXException {
		// Refresh JTree
		((DefaultTreeModel) xmlJTree.getModel()).reload();
		expandAll(xmlJTree);
	}

	public void expandAll(JTree tree) {
		int row = 0;
		while (row < tree.getRowCount()) {
			tree.expandRow(row);
			row++;
		}
	}

	public void xmlSetUp(File xmlFile) {
		try {
			SAXParserFactory fact = SAXParserFactory.newInstance();
			SAXParser parser = fact.newSAXParser();
			parser.parse(xmlFile, this);

		} catch (Exception e) {

		}
	}

	public void createUI() {

		treeModel = new DefaultTreeModel(base);
		xmlJTree = new JTree(treeModel);
		JScrollPane scrollPane = new JScrollPane(xmlJTree);

		JFrame windows = new JFrame();

		windows.setTitle("XML Tree Viewer using SAX Parser in JAVA");

		JPanel pnl = new JPanel();
		pnl.setLayout(null);
		JLabel lbl = new JLabel("File :");
		txtFile = new JTextField("Selected File Name Here");
		JButton btn = new JButton("Select File");

		btn.addActionListener(new ActionListener() {
			@Override
			public void actionPerformed(ActionEvent evt) {
				JFileChooser fileopen = new JFileChooser();
				FileFilter filter = new FileNameExtensionFilter("xml files", "xml");
				fileopen.addChoosableFileFilter(filter);

				int ret = fileopen.showDialog(null, "Open file");

				if (ret == JFileChooser.APPROVE_OPTION) {
					File file = fileopen.getSelectedFile();
					txtFile.setText(file.getPath() + File.separator + file.getName());
					xmlSetUp(file);
				}

			}
		});
		lbl.setBounds(0, 0, 100, 30);
		txtFile.setBounds(110, 0, 250, 30);
		btn.setBounds(360, 0, 100, 30);
		scrollPane.setBounds(0, 50, 500, 600);

		pnl.add(lbl);

		pnl.add(txtFile);
		pnl.add(btn);

		pnl.add(scrollPane);

		windows.add(pnl);
		windows.setSize(500, 700);
		windows.setVisible(true);
		windows.setDefaultCloseOperation( windows.EXIT_ON_CLOSE);
	}

}